Definition
Two related material properties used to describe how well a material resists being pulled apart or pushed together. Tensile strength is the maximum pulling (stretching) force a material can withstand before failing. Compressive strength is the maximum pushing (squashing) force a material can withstand before failing. In aircraft structures, these values are used to judge whether a material can safely carry the loads it will experience in flight and on the ground.
Plain English
How hard you can pull a material before it breaks apart, and how hard you can press on it before it crushes. Aircraft parts have to handle both kinds of force without failing.
Context Anchor
Seen in aircraft materials discussions, especially when comparing composite parts such as skins, panels, and structural members.
Derivation
Tensile comes from the Latin tendere, meaning to stretch. Compressive comes from the Latin comprimere, meaning to press together. The two words describe the two opposite ways a force can act on a material, which is why they are almost always discussed as a pair.
Why Pilots Care
Aircraft composites must resist both stretching and squeezing forces during flight maneuvers and landings to maintain structural integrity.
Analogy
Think of a rubber band and a soda can. The rubber band has good tensile strength, you can pull hard on it, but poor compressive strength, it just folds. The soda can is the opposite, it holds weight pressing down on it but tears easily when pulled.
Grounding Statement
Picture a wing skin being pulled in one area and squeezed in another as the airplane carries flight loads.
Intuition Check
Do not treat “strength” as one general number for all situations. In this context, tensile strength is resistance to pulling, and compressive strength is resistance to squeezing.
Example Sentence 1
Composite materials often have excellent tensile and compressive strength for their weight, which is one reason they are used in modern airframes.
Example Sentence 2
Engineers check tensile and compressive strength when choosing fuselage materials that face repeated pressure changes.